01 January 2014

Plant Based Fertilizers for Your Garden Soil

Home-grown Carrots
Carrots from the summer garden in Oregon

Recently, a reader commented on my post about using fish fertilizer that it's hard to stay away from using dead animals (bone meal) even in an organic garden.  Indeed, many organic gardeners recommend using blood and bone meal, since they are rich in nutrients the soil needs.  However, there is a strong "gross" factor that comes with these types of soil amendments, and it seems daunting to find alternatives.

I got to thinking about the plant-based soil and plant fertilizers I've used or heard about over the years, and although I've talked about a few of them before (like in my posts about using molasses and Epsom salts in the garden), there are a few more to discuss.

I'll share some links to products in this post, just for you to get some ideas of what's out there.  I won't list anything I haven't tried, or wouldn't try, in my own garden.  They won't be affiliate links.  They'll just be ideas to get you started.  But do explore your options, whether online or at a local garden or farm store.  You might be surprised to find out what's available, and what's actually great for your garden.


Between talking with friends in an informal natural remedies class about how alfalfa grows and becomes as nutrient dense as it is, and hearing the praises of alfalfa from my massage therapist, someone in my little circle of great people decided alfalfa would be a great boost for garden soil.  

I went down to the local feed store, and bought a 50-pound sack of alfalfa pellets (like you would feed to a rabbit), probably because it was cheaper than buying it in a bale.  I spread the pellets all over my flower beds turned vegetable garden as a mulch, and waited for the rain to help them break down and decay into the soil.

My observations of what happened next in the garden were not terribly scientific.  All I knew was that I gave away baskets full of tomatoes and cucumbers, and the flowers and herbs in the garden looked quite happy to be there.

I'd suggest using alfalfa as a mulch any time of year.  If you add it to your garden or raised beds in the fall, it will have time to add nutrients to the soil, but if you add it any other time around the plants as they grow, they'll be just fine.

You can order bales and boxes of alfalfa from Amazon in varying sizes (10-lb, 25-lb, and 50-lb), and they'll all qualify for free shipping if your order is over $35.  However, without too much extra thought or research, paying more than $1 per pound for alfalfa doesn't seem like a great price to me.  I'd check a feed or farm store before I would pay the Amazon price.

Soy Bean Meal

Last spring we talked often with a man who we knew had run a farm for a private school's work program.  I was eager to hear everything he had to say about gardening, and one evening we asked him to tell the story of the farm and orchard.

He grew several years of good crops, but one year floods came, wiping out everything including his soy beans.  The specialty combines he brought in to rescue the beans out of the mud couldn't do the job, so he plowed them under and planted wheat.  When he hired harvesters to cut the wheat, they couldn't believe how rich a crop he had gotten, and wanted to know how he had done it.

He answered simply, "I plowed in X number of bushels of soy beans before I planted the wheat."

I haven't found a place to buy soy bean meal yet, but we're keeping our eyes peeled.  I think it would be another great mulch to put over the soil to add all kinds of nutrients.

Kelp or Seaweed Meal

Kelp and seaweed meal are similar to blood and bone meal, but they have the benefit of being plant based.  I've used kelp meal in my garden before, and have had good results.  As I recall, the one thing to be careful of is to make sure you don't put too much in the garden, and not too often.  It's rich enough that it only takes a little to go a long way.

Amazon carries a 5-pound bag for a little less than $2 per pound, as well as a 50-pound bag for about the same price per pound.  (Amazon has more options, but those are the cheapest per pound, just to give you an idea.)  Home Depot also carries a couple of options, which you may be able to pick up in your local store:  this one is a dry meal, and this one is a liquid concentrate that can be applied weekly.

Wood Chip Mulch

Although I'm sure the idea using wood chips as mulch has been around for a long time, and I've encountered other gardeners who have used this method independently of the man in the film, I first learned about it in depth from a video called "Back to Eden", which you can watch online for free.  There is even an option with Spanish subtitles, if you're interested.  I watched the film in segments during graduate school, using it as a background to my exercise routine until I made it all the way through.

I wouldn't say I enjoyed every bit of music they use in the film, but if you're like me in that regard, you can lower the volume until the educational segments come back again.

There are three main reasons to use wood chip mulch in your garden.  First, the mulch decomposes slowly, and is constantly adding nutrition to the soil so that your garden will have richer soil the longer you use the mulch.  Second, the mulch keeps moisture in the ground longer, reducing, or in some climates even eliminating, the need for watering your garden.  Third, the mulch reduces the number of weeds that grow through it and therefore your efforts to pull the weeds.

My husband and I were able to get some wood chip mulch for free (thanks, Craigslist) this fall, and have spread it over parts of our garden beds already.  We're on the lookout for more, since we've already noticed the difference it makes in reducing our weeding and watering.

Buying Compost

For whatever reason, you may not have space or desire to start your own compost pile.  I'd still encourage you to keep your eye out at your local garden centers, on Craigslist, or even your city's compost and mulch program, because you'd be amazed at how many times you can find aged compost for sale or for free.  Your garden still benefits, but you don't have to manage the pile yourself.  

Spreading aged compost over the garden, or working it in (depending on whether you think tilling is good for your garden or not), is always a great way to feed your soil, which will in turn feed your plants.

There are many more ways to add nutrients to your soil, but I hope this gives you more ideas!  Let me know in the comments if I've missed some of your favorite ways to feed your soil--I'm still learning, too.  :)


  1. These are some great ideas! Thanks for sharing! I am hoping to get our garden spot in decent shape by next year- don't know If we will have the money or ability to do a big garden this year. Will probably have to do the smaller garden space again this year.
    I appreciate you sharing things are learning.
    Lisa :O)

  2. Oh, I hope you do have at least a small garden! It would be so refreshing for you to be out in the sunshine, watching the little plants grow. :) Keep dreaming big, though--you just never know how much your garden space might expand in the next year or two!


Greetings, fellow climbers! Leave your marks on the steps--I'll be delighted to hear from you.